I would seem that your configuration is cached, so the changes you made to the .env file had no effect.
See if you have the is file: /path/to/htdoc/boostrap/cache/config.php
If yes, execute the following command from the command line, in the htdocs folder
php artisan config:clear
Your new maximum records setting should be in effect now.
And just to be clear, since this thread was resurrected from one pertaining to the previous DF version (1.x), the .env directive is called DF_DB_MAX_RECORDS_RETURNED